Battle of Koromokina Lagoon

Battle of Koromokina Lagoon
Part of the Bougainville campaign of the Pacific Theater (World War II)
US Marines battle Japanese infantry on 8 November 1943 on Bougainville during the Battle of the Koromokina Lagoon
Date 7–8 November 1943 Location Bougainville in the South Pacific Result United States victory
Belligerents
United States	Japan
Commanders and leaders
Allen H. Turnage Oscar R. Cauldwell	Hitoshi Imamura Harukichi Hyakutake
Units involved
3rd Marines 9th Marines 12th Marines 3rd Defense Battalion	53rd Infantry 54th Infantry
Strength
17,000+	850
Casualties and losses
17 KIA and 30 WIA	377+ killed

The Battle of the Koromokina Lagoon was fought between the United States Marine Corps and Imperial Japanese Army forces on Bougainville Island. It took place on 7–8 November 1943 during the Bougainville campaign of the Pacific War.

In response to the Allied landings on Bougainville at Cape Torokina, Japanese General Hitoshi Imamura, commander of the 8th Area Army at Rabaul, determined to launch a counterattack. Underestimating the size of the Allied landing forces, the Japanese dispatched a force of 850 soldiers to execute a counter landing to attempt to drive the Allied forces back into the sea. The Japanese soldiers landed from four destroyers near Koromokina Lagoon on the night of 7 November and engaged two battalions of U.S. Marines from the 3rd and 9th Marine Regiments under the command of Major General Allen H. Turnage.

Over the next two days the Japanese attacks were defeated with heavy losses to the attackers. After the battle, Allied forces continued to expand their beachhead on Bougainville with the goal of constructing airfields to attack and neutralize Japanese forces located at Rabaul and nearby areas.